JP2009058647A - Liquid crystal device and method for manufacturing liquid crystal device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal device with which high contrast is obtained without using an optical compensation film, and a method for manufacturing the liquid crystal device. <P>SOLUTION: The liquid crystal device 100 includes a liquid crystal layer 50 interposed between a pair of substrates 10, 20. Alignment layers 40, 60 are arranged on the liquid crystal layer 50 sides of the substrates 10, 20. The alignment layers 40, 60 include low-molecular weight molecular deposition films 40b, 60b with which an alignment direction of a liquid crystal molecule can be varied from an initial alignment state. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a liquid crystal device and a method for manufacturing the liquid crystal device.

  A liquid crystal device used as a light valve mounted on a projection display device has, for example, a configuration in which a liquid crystal layer is sandwiched between a pair of substrates arranged to face each other, and the liquid crystal layer on the liquid crystal layer side of these substrates. Are provided with electrodes for applying a voltage. In this liquid crystal device, an alignment film for controlling the alignment of liquid crystal molecules when no voltage is applied is formed on the outermost surface of the pair of substrates on the liquid crystal layer side. The display is performed based on the arrangement change. Thus, contrast is important in the liquid crystal device used as the light modulation means, and the VA (vertical alignment) mode is adopted as the operation mode.

By the way, in the conventional VA mode liquid crystal device, in order to tilt the liquid crystal in one direction by forming an electric field, it is necessary to be in a state tilted by several degrees (pretilt alignment) with respect to the normal direction of the substrate in the absence of voltage application. is there. Thus, if a pretilt is imparted to the liquid crystal molecules, the viewing angle characteristics and contrast may be degraded. Therefore, a technique is known in which optical compensation films such as an NH film and a WV film are arranged before and after the liquid crystal device in order to ensure viewing angle characteristics and contrast (see, for example, Patent Documents 1 and 2).
JP 2006-330522 A JP 2005-114918 A

  However, since the optical compensation film has a high component cost, it is desired to provide a liquid crystal device (light valve) capable of obtaining high contrast without using the optical compensation film.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a liquid crystal device that obtains high contrast without using an optical compensation film, and a method for manufacturing the liquid crystal device.

  In order to solve the above problems, a liquid crystal device of the present invention is a liquid crystal device in which a liquid crystal layer is sandwiched between a pair of substrates, and an alignment film is provided on the liquid crystal layer side of the substrate, and the alignment The film includes a low molecular vapor deposition film that allows the alignment direction of liquid crystal molecules to be changed from the initial alignment state.

  According to the liquid crystal device of the present invention, for example, even in a vertical alignment film in which the pretilt of the entire alignment film is set to 0 °, the tilt angle of the liquid crystal molecules can be controlled in one direction when a voltage is applied by the low molecular vapor deposition film. In this way, by setting the pretilt angle to 0 °, the optical film is not required, thereby reducing the cost and preventing the viewing angle characteristics and the contrast from being lowered.

The liquid crystal device of the present invention is a liquid crystal device in which a liquid crystal layer is sandwiched between a pair of substrates.
An alignment film is provided on the liquid crystal layer side of the substrate. The alignment film is provided on a surface treatment layer formed by a predetermined surface treatment and the surface treatment layer, and the orientation of liquid crystal molecules is initially set. It is characterized by comprising a laminated structure with a low molecular vapor deposition film that can be changed from the orientation.

  According to the liquid crystal device of the present invention, the tilt angle of liquid crystal molecules is controlled in one direction when a voltage is applied by a low molecular vapor deposition film even in a vertical alignment film in which the pre-tilt of the entire alignment film is set to 0 ° by a surface treatment layer, for example. be able to. In this way, by setting the pretilt angle to 0 °, the optical film is not required, thereby reducing the cost and preventing the viewing angle characteristics and the contrast from being lowered.

In the liquid crystal device, the low molecular vapor deposition film is preferably made of a material that does not absorb light in the visible light region.
If this material is used, the low molecular vapor deposition film does not have a light absorption property, so that it has excellent light resistance.

In the liquid crystal device, the low molecular vapor deposition film is preferably made of an organic-inorganic hybrid material. The organic / inorganic hybrid material is more preferably silsesquioxanes.
If this material is used, a low molecular vapor deposition film that makes it possible to control the tilt angle of liquid crystal molecules in one direction as described above can be satisfactorily constructed.

In the liquid crystal device, the material for forming the low molecular vapor deposition film is preferably adamantane.
Alternatively, in the liquid crystal device, the material for forming the low molecular vapor deposition film may be paracyclopane.
By using these materials, it is possible to satisfactorily configure a low molecular vapor deposition film that can control the tilt angle of liquid crystal molecules in one direction as described above.

  The method for manufacturing a liquid crystal device according to the present invention includes a step of forming an alignment film on one surface side of the substrate in a method for manufacturing a liquid crystal device in which a liquid crystal layer is sandwiched between a pair of substrates. The forming step includes a step of forming a low molecular vapor deposition film that can change the alignment direction of the liquid crystal molecules from the initial alignment state by using a vapor deposition method.

  According to the method for manufacturing a liquid crystal device of the present invention, for example, even in a vertical alignment film in which the pretilt of the entire alignment film is set to 0 °, the tilt angle of liquid crystal molecules is controlled in one direction when a voltage is applied by a low molecular vapor deposition film. Can do. Thus, by setting the pretilt angle to 0 °, it is possible to provide a liquid crystal device in which the viewing angle characteristics and the contrast are prevented from being lowered without using an optical compensation film.

  The method for manufacturing a liquid crystal device according to the present invention is a method for manufacturing a liquid crystal device in which a liquid crystal layer is sandwiched between a pair of substrates, and a predetermined surface treatment is performed on one side of the substrate to form a surface treatment layer. And a step of forming a low molecular vapor deposition film that can change the alignment direction of the liquid crystal molecules from the initial alignment state on the surface treatment layer by using a vapor deposition method.

  According to the method for manufacturing a liquid crystal device of the present invention, the low molecular vapor deposition film is formed on the surface treatment layer in which the pretilt angle as the whole alignment film is set to 0 °. A vertical alignment film with a pretilt set to 0 ° can be formed, and the tilt angle of liquid crystal molecules can be controlled in one direction when a voltage is applied. Thus, by setting the pretilt angle to 0 °, it is possible to provide a liquid crystal device in which the viewing angle characteristics and the contrast are prevented from being lowered without using an optical compensation film.

In the method for manufacturing the liquid crystal device, it is preferable to use a material that does not absorb light in the visible light region as the material for forming the low molecular vapor deposition film.
If this material is used, a liquid crystal device excellent in light resistance can be provided by forming a low molecular vapor deposition film having no light absorption.

Moreover, in the manufacturing method of the liquid crystal device, it is preferable to use an organic-inorganic hybrid material as a material for forming the low molecular vapor deposition film. Furthermore, it is desirable to use a silsesquioxane material as the organic-inorganic hybrid material.
By using this material, as described above, a low molecular vapor deposition film capable of controlling the tilt angle of the liquid crystal molecules in one direction can be favorably formed.

In the method for manufacturing a liquid crystal device, it is preferable to use an adamantane-based material as a material for forming the low molecular vapor deposition film.
Alternatively, in the method for manufacturing the liquid crystal device, it is preferable to use paracyclopan as a material for forming the low molecular vapor deposition film.
By using such a material, it is possible to satisfactorily form a low molecular vapor deposition film capable of controlling the tilt angle of liquid crystal molecules in one direction as described above.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

  FIG. 1 is an equivalent circuit diagram of switching elements, signal lines, and the like in a plurality of pixels arranged in a matrix that constitutes an image display region of the transmissive liquid crystal device of this embodiment. FIG. 2 is a plan view showing the structure of a plurality of pixel groups adjacent to each other on a TFT array substrate on which data lines, scanning lines, pixel electrodes and the like are formed. FIG. 3 is a cross-sectional view of the element region of the transmissive liquid crystal device of this embodiment, and is a cross-sectional view taken along the line A-A ′ of FIG. 2. FIG. 4 is a cross-sectional view schematically showing a plurality of pixel regions in the transmissive liquid crystal device of this embodiment. 3 and 4, the upper side in the drawing is the light incident side, and the lower side in the drawing is the viewing side (observer side).

  In the transmissive liquid crystal device according to the present embodiment, as shown in FIG. 1, a plurality of pixels arranged in a matrix that constitutes an image display region are subjected to energization control for the pixel electrode 9 and the pixel electrode 9. TFT elements 30 as the switching elements are formed, and the data line 6 a to which an image signal is supplied is electrically connected to the source of the TFT element 30. Image signals S1, S2,..., Sn to be written to the data line 6a are supplied line-sequentially in this order, or are supplied for each group to a plurality of adjacent data lines 6a.

  In addition, the scanning line 3a is electrically connected to the gate of the TFT element 30, and scanning signals G1, G2,..., Gm are applied to the plurality of scanning lines 3a in a pulse-sequential manner at predetermined timing. The Further, the pixel electrode 9 is electrically connected to the drain of the TFT element 30, and the image signal S1, S2,... Supplied from the data line 6a is turned on by turning on the TFT element 30 as a switching element for a certain period. , Sn is written at a predetermined timing.

  A predetermined level of image signals S1, S2,..., Sn written to the liquid crystal via the pixel electrode 9 is held for a certain period with the common electrode described later. The liquid crystal modulates light by changing the orientation and order of the molecular assembly according to the applied voltage level, thereby enabling gradation display. Here, in order to prevent the held image signal from leaking, a storage capacitor 70 is added in parallel with the liquid crystal capacitor formed between the pixel electrode 9 and the common electrode.

  Next, the planar structure of the transmissive liquid crystal device of this embodiment will be described with reference to FIG. As shown in FIG. 2, a rectangular pixel electrode 9 (outlined by a dotted line portion 9A) made of a transparent conductive material such as indium tin oxide (hereinafter abbreviated as “ITO”) is formed on the TFT array substrate. A plurality of pixels are provided in a matrix, and data lines 6 a, scanning lines 3 a, and capacitor lines 3 b are provided along the vertical and horizontal boundaries of the pixel electrode 9. In the present embodiment, each pixel electrode 9 and the area where the data line 6a, the scanning line 3a, the capacitor line 3b, etc. are arranged so as to surround each pixel electrode 9 are pixels, and are arranged in a matrix. The display can be displayed for each pixel.

  The data line 6a is electrically connected to a source region (described later) through a contact hole 5 in the semiconductor layer 1a made of, for example, a polysilicon film constituting the TFT element 30, and the pixel electrode 9 is connected to the semiconductor layer 1a. Among these, it is electrically connected to a drain region described later via a contact hole 8. In addition, the scanning line 3a is disposed so as to face a channel region (a region with a diagonal line rising to the left in the figure), which will be described later, in the semiconductor layer 1a, and the scanning line 3a serves as a gate electrode at a portion facing the channel region. Function.

  The capacitor line 3b is formed from a main line portion extending in a substantially straight line along the scanning line 3a (that is, a first region formed along the scanning line 3a in a plan view) and a portion intersecting the data line 6a. And a protruding portion (that is, a second region extending along the data line 6 a when viewed in a plan view) protruding toward the previous stage (upward in the drawing) along the data line 6 a. In FIG. 2, a plurality of first light shielding films 11 a are provided in a region indicated by a diagonal line rising to the right.

  Next, a cross-sectional structure of the transmissive liquid crystal device of this embodiment will be described with reference to FIGS. In FIG. 4, some components such as switching elements are omitted in view of the visibility of the drawing. As shown in FIGS. 3 and 4, in the transmissive liquid crystal device of the present embodiment, a TFT array substrate (liquid crystal device substrate) 10 and a counter substrate (liquid crystal device substrate) 20 disposed opposite thereto are provided. A liquid crystal layer 50 is sandwiched therebetween.

  The TFT array substrate 10 is mainly composed of a substrate 10A made of a translucent material such as quartz, a pixel electrode 9 formed on the surface of the liquid crystal layer 50, and an alignment film 40. The counter substrate 20 is made of glass or quartz. The substrate 20A made of a translucent material such as the common electrode 21 and the alignment film 60 formed on the surface of the liquid crystal layer 50 are mainly used. Further, as shown in FIG. 3, in the TFT array substrate 10, pixel electrodes 9 are provided on the surface of the substrate 10 </ b> A on the liquid crystal layer 50 side, and each pixel electrode 9 is subjected to switching control at a position adjacent to each pixel electrode 9. A pixel switching TFT element 30 is provided.

  The pixel switching TFT element 30 has an LDD (Lightly Doped Drain) structure, and includes a scanning line 3a, a channel region 1a ′ of the semiconductor layer 1a in which a channel is formed by an electric field from the scanning line 3a, and the scanning line 3a. A gate insulating film 2 that insulates the semiconductor layer 1a, a data line 6a, a low concentration source region 1b and a low concentration drain region 1c of the semiconductor layer 1a, and a high concentration source region 1d and a high concentration drain region 1e of the semiconductor layer 1a. ing.

  In addition, on the substrate 10A including the scanning line 3a and the gate insulating film 2, a contact hole 5 leading to the high concentration source region 1d and a contact hole 8 leading to the high concentration drain region 1e are opened. An insulating film 4 is formed. That is, the data line 6 a is electrically connected to the high concentration source region 1 d through the contact hole 5 that penetrates the second interlayer insulating film 4. Further, on the data line 6a and the second interlayer insulating film 4, a third interlayer insulating film 7 having a contact hole 8 leading to the high concentration drain region 1e is formed. That is, the high concentration drain region 1 e is electrically connected to the pixel electrode 9 through the contact hole 8 that penetrates the second interlayer insulating film 4 and the third interlayer insulating film 7.

  In the present embodiment, the gate insulating film 2 is extended from a position facing the scanning line 3a and used as a dielectric film, the semiconductor layer 1a is extended to form the first storage capacitor electrode 1f, and further opposed thereto. The storage capacitor 70 is configured by using a part of the capacitor line 3b to be a second storage capacitor electrode.

  On the surface of the TFT array substrate 10 on the liquid crystal layer 50 side of the substrate 10 </ b> A, the TFT switching substrate 30 is transmitted through the region where the pixel switching TFT elements 30 are formed, and the lower surface of the TFT array substrate 10 (the TFT array substrate 10 is illustrated). For preventing the return light reflected at the interface between the liquid crystal layer 50 and the liquid crystal layer 50 from entering at least the channel region 1a ′ and the low concentration source / drain regions 1b and 1c of the semiconductor layer 1a. One light shielding film 11a is provided. Further, a first interlayer insulation for electrically insulating the semiconductor layer 1a constituting the pixel switching TFT element 30 from the first light shielding film 11a is provided between the first light shielding film 11a and the pixel switching TFT element 30. A film 12 is formed. Further, as shown in FIG. 2, in addition to providing the first light-shielding film 11a on the TFT array substrate 10, the first light-shielding film 11a is electrically connected to the capacitor line 3b at the preceding stage or the subsequent stage through the contact hole 13. Configured to connect to.

  An alignment film 40 that vertically aligns liquid crystal molecules in the liquid crystal layer 50 when no voltage is applied is provided on the outermost surface of the TFT array substrate 10 on the liquid crystal layer 50 side, that is, on the pixel electrode 9 and the third interlayer insulating film 7. Is formed. This alignment film 40 is formed based on the manufacturing method according to the present invention described later.

  On the other hand, the counter substrate 20 has a surface on the liquid crystal layer 50 side of the substrate 20A, which is opposed to the formation region of the data line 6a, the scanning line 3a, and the pixel switching TFT element 30, that is, other than the opening region of each pixel portion. Is provided with a second light-shielding film 23 for preventing incident light from entering the channel region 1a ′, the low concentration source region 1b, and the low concentration drain region 1c of the semiconductor layer 1a of the pixel switching TFT element 30. It has been. Further, a common electrode 21 made of ITO or the like is formed on the liquid crystal layer 50 side of the substrate 20A on which the second light shielding film 23 is formed, and no voltage is applied to the liquid crystal layer 50 side. An alignment film 60 that vertically aligns the liquid crystal molecules in the liquid crystal layer 50 is formed. This alignment film 60 is also formed based on the manufacturing method according to the present invention described later.

  Here, the alignment films 40 and 60 are configured by forming low molecular vapor deposition films 40b and 60b on the surface treatment layers 40a and 60a. The surface treatment layers 40a and 60a are made of a material having a function of vertically aligning liquid crystal molecules such as a silane coupling material (saturated hydrocarbon-based siloxane), for example. It is formed so as to cover the pixel electrode 9.

  The low molecular vapor deposition films 40b and 60b are made of a material that does not absorb light in the visible light region, for example, an organic-inorganic hybrid material such as a silsesquioxane low molecular weight material. An organic-inorganic hybrid material is a material in which both an organic component and an inorganic component are present in the same molecule and has an inorganic skeleton, and thus has higher heat resistance and light resistance than a polymer material.

Since the surface treatment layers 40a and 60a can set the pretilt angle to 0 °, the direction in which the liquid crystal molecules fall cannot be controlled.
On the other hand, the low molecular vapor deposition films 40b and 60b are formed by obliquely vapor-depositing an organic-inorganic hybrid material as will be described later in a vacuum environment, and between the electrodes 9 and 21 without performing a rubbing process. When a voltage is applied, it exerts an alignment regulating force that makes it possible to change the alignment direction of the liquid crystal molecules from the initial alignment state. That is, the alignment films 40 and 60 of the liquid crystal device according to the present embodiment are formed by the low molecular vapor deposition films 40b and 60b while the pre-tilt angle of the alignment films 40 and 60 as a whole is maintained at 0 ° by the surface treatment layers 40a and 60b. The tilt direction of the liquid crystal molecules can be controlled. Further, in the liquid crystal device according to the present embodiment, when the rubbing process is performed as in the prior art, the display quality is not deteriorated due to the streaks formed on the film surface, and the yield is reduced due to the rubbing process. Therefore, the display quality of the liquid crystal device 100 is improved and the manufacturing efficiency is improved.

  In the present embodiment, an organic-inorganic hybrid material of silsesquioxane represented by the following chemical formulas (1) to (63) is preferably used as a material for forming the low molecular vapor deposition films 40b and 60b. it can.

  Next, an embodiment of a method for manufacturing the liquid crystal device 100 will be described. In addition, since the manufacturing method of the liquid crystal device according to the present invention has a feature in the manufacturing method of the alignment film, and the other manufacturing processes are the same as the conventional method, in the following description, the forming method of the alignment film is described. The explanation is centered. Specifically, a method for forming the alignment film 40 included in the TFT array substrate 10 will be described. Note that the alignment film 60 included in the counter substrate 20 can be similarly formed by the manufacturing method of the present invention.

  First, a translucent substrate 10A made of glass or the like is prepared, and a first light shielding film 11a, a first interlayer insulating film 12, a semiconductor layer 1a, various wirings 3a, 3b, 6a, insulating films 4, 7 and pixels are prepared. The electrode 9 and the like are formed by a known method. Then, an alignment film 40 is formed on the third interlayer insulating film 7 including the pixel electrode 9 formed on the substrate 10A.

As described above, the alignment film 40 is configured by forming the low molecular vapor deposition films 40b and 60b on the surface treatment layers 40a and 60a. Therefore, first, a process of forming the surface treatment layers 40a and 60a will be described.
In the present embodiment, the above-described silane coupling (saturated hydrocarbon siloxane) is used as a surface treatment material, and the surface treatment layer 40a is formed by a surface treatment apparatus.

FIG. 5 is an overall view showing a schematic configuration of the surface treatment apparatus used in the present embodiment.
As shown in this figure, the surface treatment apparatus 200 of the present embodiment performs a predetermined surface treatment on the third interlayer insulating film 7 including the pixel electrode 9, and includes an evaporator 202, a treatment apparatus 203, A vacuum pump 204 and a control device 205 are provided. The predetermined surface treatment is a surface treatment that enables the production of the surface treatment layer 40a provided with a function as a vertical alignment film for vertically aligning liquid crystal molecules.

The evaporator 202 vaporizes the liquid silane coupling agent Y1 stored inside. The evaporator 202 is connected to a carrier gas supply pipe 206 for supplying a carrier gas necessary for vaporizing the silane coupling agent Y 1 into the evaporator 202. Further, the evaporator 202 is connected to the processing apparatus 203 via a pipe 207. The carrier gas is selected according to the type of silane coupling agent Y1 stored in the evaporator 202, and for example, nitrogen gas or argon gas can be used.
The evaporator 202 includes a heater, a pressure adjustment valve, and the like (not shown). These heaters and pressure regulating valves are controlled by the control device 205, whereby the internal atmosphere of the evaporator 202 is controlled. That is, the processing atmosphere inside the evaporator 202 is controlled by the control device 205.

In the processing apparatus 203, the substrate 10 </ b> A that is an object to be processed is disposed inside, and the vaporized silane coupling agent Y <b> 2 is introduced from the evaporator 202 via the pipe 207. The substrate 10A is supported by a support portion (not shown).
The processing apparatus 203 includes a heater, a pressure adjustment valve, and the like (not shown). These heaters and pressure regulating valves are controlled by the control device 205, whereby the internal atmosphere of the processing device 203 is controlled. That is, the processing atmosphere inside the processing device 203 is controlled by the control device 205. Specifically, in this embodiment, the processing atmosphere of the processing apparatus 203 is controlled to 150 ° C. to 200 ° C.

Further, a vacuum pump 204 is connected to the processing apparatus 203 via a pipe 208.
The vacuum pump 204 is driven under the control of the control device 205, discharges the air inside the processing device 203, and forms a vacuum atmosphere inside the processing device 203.

As described above, the control device 205 controls the evaporator 202, the processing device 203, and the vacuum pump 204, and is electrically connected to each of the evaporator 202, the processing device 203, and the vacuum pump 204.
And in the surface treatment apparatus 200 of this embodiment, the control apparatus 205 can control separately the process atmosphere inside the evaporator 202, and the process atmosphere inside the processing apparatus 203. FIG. More specifically, the control device 205 controls the processing atmosphere inside the evaporator 202 by controlling the heater and pressure adjustment valve of the evaporator 202, and controls the heater and pressure adjustment valve of the processing device 203. The processing atmosphere inside 203 is controlled. The control device 205 can independently control the heater of the evaporator 202, the pressure adjustment valve of the evaporator 202, the heater of the processing device 203, and the pressure adjustment valve of the processing device 203. The internal processing atmosphere and the internal processing atmosphere of the processing apparatus 203 can be individually controlled.
The control device 205 sets the processing atmosphere inside the evaporator 202 to the optimum conditions for vaporizing the silane coupling agent Y1, and sets the processing atmosphere inside the processing device 203 to the optimum conditions for surface treatment by the vaporized silane cupping agent Y2. .

  The optimum conditions for vaporizing the silane coupling agent Y1 are conditions under which the silane coupling agent Y1 vaporizes in the shortest time in a controllable processing atmosphere. That is, in the surface treatment apparatus 200 of this embodiment, the temperature and pressure inside the evaporator 202 are controlled by the control device 205 to the conditions under which the silane coupling agent Y1 is vaporized in the shortest time.

  Further, the optimum conditions for the surface treatment with the vaporized silane coupling agent Y2 are the conditions for completing the surface treatment in the shortest time in a controllable treatment atmosphere. Completing the surface treatment is equivalent to forming a silane coupling agent having a predetermined thickness on the surface of the substrate 10A. That is, in the surface treatment apparatus 200 of this embodiment, the control device 205 forms a silane coupling agent having a predetermined film thickness on the surface of the substrate 10A in the shortest time with the temperature and pressure inside the treatment apparatus 203. Controlled by the conditions.

Next, a surface treatment method using the surface treatment apparatus 200 will be specifically described.
First, the processing atmosphere inside the evaporator 202 is set to an optimum condition for vaporizing the silane coupling agent Y1 by the control device 205. Further, the vacuum pump 204 is driven by the control device 205 to make the inside of the processing device 203 a vacuum atmosphere, and the surface treatment with the silane cup agent Y2 in which the processing atmosphere inside the processing device 203 is vaporized by the control device 205. It is considered to be the optimal condition.

When the carrier gas is supplied to the evaporator 202 through the carrier gas supply pipe 206, the silane coupling agent Y1 is vaporized in the evaporator 202. The vaporized silane coupling agent Y2 is introduced into the processing apparatus 203 via the pipe 207.
By introducing the vaporized silane coupling agent Y2 into the processing apparatus 203, the inside of the processing apparatus 203 is filled with the silane coupling agent Y2. Since the substrate 10A is disposed inside the processing apparatus 203, the substrate 10A is exposed to the atmosphere present in the vaporized silane coupling agent Y2. As a result, a silane coupling agent is formed on the surface of the substrate 10A. That is, the surface of the substrate 10A is surface-treated with the silane coupling agent. The surface treatment is preferably performed for 1 to 4 hours, whereby a surface treatment layer 40a having a thickness of about 1 nm is formed on the surface of the substrate 10A. The surface treatment layer 40a has a function of vertically aligning liquid crystal molecules, and the pretilt angle is 0 °.

  Next, a process of forming the alignment film 40 by forming the low molecular vapor deposition film 40b on the surface treatment layer 40a will be described. In the present embodiment, the low molecular vapor deposition film 40b is formed by a vapor deposition apparatus using the organic-inorganic hybrid material described above.

  FIG. 6 is an overall view showing a schematic configuration of a vapor deposition apparatus used in the present embodiment. The vapor deposition apparatus 300 includes a vapor deposition source 302 made of the organic-inorganic hybrid material described above, and a substrate disposition unit 307 that disposes the substrate 10A at a predetermined angle (60 degrees or more) with respect to the vapor deposition source 302. A vapor deposition chamber 308 and a vacuum pump 310 for evacuating the vapor deposition chamber 308 are provided. In addition, in the vapor deposition apparatus 300 of this embodiment, as shown in FIG.6 (b), the linear vapor deposition source 302a is used as the said vapor deposition source 302. As shown in FIG.

  By using the linear vapor deposition source 302b, the material spreads over a wide range along the line direction (longitudinal direction) as shown in FIG. 6B. Therefore, the line-shaped vapor deposition source 302b has a higher uniformity of material distribution in the line direction than the case where a point-shaped vapor deposition source in which the material is distributed radially is used, and thus the material is uniformly deposited along the line direction. can do. In addition, the length of the said linear vapor deposition source 302a is substantially the same as the width | variety of the board | substrate 10A used as a to-be-deposited body. Thus, the low molecular vapor deposition film 40b made of the organic-inorganic hybrid material is formed on the substrate 10A by moving the substrate 10A in the direction of arrow A in FIG. 5A with respect to the linear vapor deposition source 302a. be able to.

  A pair of regulation plates 303 are provided between the line-shaped vapor deposition source 302a and the substrate 10A so as to face each other with the line-shaped vapor deposition source 302a interposed therebetween. The restriction plate 303 is provided along the line direction, that is, along the longitudinal direction of the line-shaped vapor deposition source 302a shown in FIG. With such a configuration, spreading of the vapor deposition material (organic-inorganic hybrid material) in a direction orthogonal to the line direction (longitudinal direction) is regulated by the regulation plate 303.

  Further, a heating means such as a lamp heater (not shown) is provided on the outer surface side of the regulation plate 303, whereby at least the inner surface side of the regulation plate 303 is a heated surface. Further, as the heating means, a resistance heating type in which a nichrome wire or the like is embedded in the regulation plate 303 may be adopted. It is desirable that the temperature of the heating surface be a temperature at which the material does not adhere to the heating surface when the material (organic-inorganic hybrid material) evaporated from the linear vapor deposition source 302b collides. Thereby, when the said material collides, material is reflected, without adhering to the inner surface (heating surface) of the control board 303. FIG.

  Next, a method for forming the low molecular vapor deposition film 40b on the substrate 10A using the vapor deposition apparatus 300 will be specifically described. First, when the vacuum pump 310 is operated, the vapor deposition chamber 308 is evacuated, and when the vapor deposition source 302 is further heated by a heating device (not shown), vapor of the organic-inorganic hybrid material is generated from the vapor deposition source 302.

  Of the materials from the vapor deposition source 302, the material that spreads in the direction perpendicular to the line direction spreads in the region sandwiched by the restriction plates 303. In this embodiment, although the regulation plate 303 is formed only along the line direction as described above, a linear plate (line deposition source 302b) is used as the deposition source 302. Even if not provided, the material spreads uniformly in the line direction.

The material spread from the vapor deposition source 302 collides with the regulation plate 303. At this time, since the inner surface side of the regulation plate 303 is a heating surface as described above, the material is reflected without adhering to the inner surface side of the regulation plate 303.
The material distribution in the orthogonal direction (the orthogonal direction of the line direction) of the restriction plate 303 is made uniform by repeating the collision and reflection of the material in the region sandwiched between the restriction plates 303. That is, since the material has a uniform distribution in the above-described line direction and the direction orthogonal to the line direction, a uniform film-like body can be formed on the substrate 10A.

  The material is deposited on the surface of the substrate 10A at a predetermined angle after passing through the region sandwiched between the regulating plates 303. Here, although the material after passing through the regulation plate 303 has a uniform distribution, the directionality of each particle varies. In the present vapor deposition apparatus 300, by arranging the end portion of the regulating plate 303 and the substrate 10A apart from each other by a predetermined distance, no material other than the desired direction is deposited on the substrate 10A. A low molecular vapor deposition film 40b having a predetermined direction can be formed on the surface treatment layer 40a. The film thickness of the low molecular vapor deposition film 40b is preferably about 5 to 10 nm.

  Through the above steps, the alignment film 40 having a laminated structure of the surface treatment layer 40a and the low molecular vapor deposition film 40b is formed on the substrate 10A. After the TFT array substrate 10 having such an alignment film 40 is formed, the counter substrate 20 is formed. In this case, after preparing the substrate 20A made of a transparent material, the light shielding film 23 and the common electrode 21 are formed on the substrate 20A by using the same method as the manufacturing process of the TFT array substrate 10, and further, the figure is further formed thereon. The counter substrate 20 can be formed by forming the alignment film 60 using the surface treatment apparatus 200 and the vapor deposition apparatus 300 shown in FIGS.

  Thereafter, the TFT array substrate 10 and the counter substrate 20 are bonded together through a sealing material, and liquid crystal is injected from a liquid crystal injection port formed in the sealing material to form a liquid crystal panel, and then a predetermined wiring is connected, The liquid crystal device 100 described above can be manufactured.

As described above, the liquid crystal device 100 manufactured by the manufacturing method according to the present embodiment includes the alignment films 40 and 60 that form the vertical alignment film whose pretilt angle is set to 0 ° by the surface treatment layers 40a and 60a. Therefore, the low molecular vapor deposition films 40b and 60b can align the liquid crystal molecules in a predetermined direction when a voltage is applied. Thus, since the pretilt angle of the alignment films 40 and 60 as a whole is set to 0 °, the viewing angle characteristic and the contrast are not deteriorated due to the pretilt angle. Therefore, the liquid crystal device 100 can be obtained with high contrast display and cost reduction without using an optical compensation film such as an NH film or a WV film. In addition, in the manufacturing method according to the present embodiment, unlike the conventional method, the rubbing process when forming the alignment film is unnecessary, and therefore, the display caused by the streaks formed on the film surface when the rubbing process is performed. Degradation can be prevented and yield can be improved. In addition, since the alignment films 40 and 60 are not composed of an inorganic vapor deposition film, it can be made less susceptible to the influence of humidity.
Moreover, since the low molecular vapor deposition films 40b and 60b that regulate the orientation direction of liquid crystal molecules when a voltage is applied are not in the shape orientation but in the molecular orientation, the intermolecular force is strong and a high orientation regulating force can be obtained.
Such a liquid crystal device 100 is suitable as a light modulation device of a projection display device as will be described later.

(Projection type display device)
Next, a configuration of a projection display device (projector) including the liquid crystal device of the above embodiment as a light modulation unit will be described with reference to FIG. FIG. 7 is a schematic configuration diagram showing a main part of a projection display device using the liquid crystal device of the embodiment as a light modulation device. In FIG. 7, 810 is a light source, 813 and 814 are dichroic mirrors, 815, 816 and 817 are reflection mirrors, 818 is an incident lens, 819 is a relay lens, 820 is an exit lens, 822, 823 and 824 are liquid crystal light modulators, Reference numeral 825 denotes a cross dichroic prism, and reference numeral 826 denotes a projection lens.

  The light source 810 includes a lamp 811 such as a metal halide and a reflector 812 that reflects the light of the lamp. The dichroic mirror 813 that reflects blue light and green light transmits red light out of the light flux from the light source 810 and reflects blue light and green light. The transmitted red light is reflected by the reflection mirror 817 and is incident on the red light liquid crystal light modulation device 822 including the liquid crystal device as an example of the present invention.

  On the other hand, of the color light reflected by the dichroic mirror 813, the green light is reflected by the dichroic mirror 814 that reflects green light, and enters the liquid crystal light modulator 823 for green light that includes the above-described liquid crystal device according to the present invention. . Note that the blue light also passes through the second dichroic mirror 814. For blue light, light guide means 821 comprising a relay lens system including an incident lens 818, a relay lens 819, and an exit lens 820 is provided in order to compensate for the difference in optical path length from green light and red light. Through this, the blue light is incident on the liquid crystal light modulation device 824 for blue light provided with the liquid crystal device as an example of the present invention.

  The three color lights modulated by the respective light modulation devices are incident on the cross dichroic prism 825. In this prism, four right-angle prisms are bonded together, and a dielectric multilayer film that reflects red light and a dielectric multilayer film that reflects blue light are formed in a cross shape on the inner surface. These dielectric multilayer films combine the three color lights to form light representing a color image. The synthesized light is projected onto the screen 827 by the projection lens 826 which is a projection optical system, and the image is enlarged and displayed.

  Since the projection type display device having the above-described structure includes the liquid crystal device as an example of the present invention described above, there is no problem that rubbing streaks are displayed, for example, when the rubbing process is performed, and the display quality is improved. The display device can be maintained for a long time. In addition, an optical compensation film can be made unnecessary even in a projection display device that includes the alignment films 40 and 60 having a pretilt angle set to 0 ° and in which the contrast is regarded as important, and the cost can be reduced. .

The technical scope of the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.
For example, in the above embodiment, an organic-inorganic hybrid material (silsesquioxane) is used as a material for forming the low molecular vapor deposition films 40b and 60b. However, the present invention is not limited to this, and in the visible light range. Paracyclopane represented by the following chemical formula (64), which is a material having no light absorption property, may be used.

  Further, as the material for forming the low molecular vapor deposition films 40b and 60b, adamantane derivatives represented by the following chemical formulas (65) to (113), which are materials having no light absorption property in the visible light region, may be used. In the case where the low molecular vapor deposition films 40b and 60b are formed using the adamantane derivative, the surface treatment layers 40a and 60a can be dispensed with, and only the single adamantane derivative layer has a pretilt angle of 0 ° and A vertical alignment film that regulates the alignment direction of liquid crystal molecules when a voltage is applied can be formed.

  For example, in the above embodiment, a liquid crystal device including a TFT as a switching element has been described as an example. However, the present invention is applied to a liquid crystal device including a two-terminal element such as a thin film diode as a switching element. It is also possible. Further, although the transmissive liquid crystal device has been described as an example in the above embodiment, the present invention can also be applied to a reflective liquid crystal device. Further, in the embodiment, the description has been given by taking a three-plate projection display device (projector) as an example, but the present invention can also be applied to a single-plate projection display device or a direct-view display device.

The liquid crystal device can also be applied to electronic devices other than the projection display device.
A specific example is a mobile phone. This mobile phone includes the liquid crystal device according to each of the above-described embodiments or modifications thereof in a display unit. Other electronic devices include, for example, IC cards, video cameras, personal computers, head-mounted displays, fax machines with display functions, digital camera finders, portable TVs, DSP devices, PDAs, electronic notebooks, and electronic bulletin boards. And advertising announcement displays.

It is a figure which shows the equivalent circuit in a liquid crystal device. It is a figure which shows the structure of the pixel group which a TFT array substrate mutually adjoins. It is a figure which shows the element structure of a liquid crystal device. It is a figure which shows the structure of a pixel area | region typically. It is a figure which shows schematic structure of a surface treatment apparatus. It is a figure which shows schematic structure of a vapor deposition apparatus. It is an example about the projection type display apparatus provided with the liquid crystal device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... TFT array substrate (substrate), 20 ... Counter substrate (substrate), 40 ... Alignment film, 50 ... Liquid crystal layer, 40a ... Base treatment layer, 40b ... Low molecular vapor deposition film, 60 ... Alignment film, 60a ... Base treatment layer 60b ... Low molecular vapor deposition film, 100 ... Liquid crystal device

Claims (14)

In a liquid crystal device in which a liquid crystal layer is sandwiched between a pair of substrates,
An alignment film is provided on the liquid crystal layer side of the substrate,
The liquid crystal device, wherein the alignment film includes a low molecular vapor deposition film that allows the alignment direction of liquid crystal molecules to be changed from the initial alignment state. In a liquid crystal device in which a liquid crystal layer is sandwiched between a pair of substrates,
An alignment film is provided on the liquid crystal layer side of the substrate,
The alignment film has a laminated structure of a surface treatment layer formed by a predetermined surface treatment and a low molecular vapor deposition film provided on the surface treatment layer and capable of changing the orientation of liquid crystal molecules from the initial orientation. A liquid crystal device characterized by the above.   The liquid crystal device according to claim 1, wherein the low molecular vapor deposition film is made of a material that does not absorb light in a visible light region.   The liquid crystal device according to claim 3, wherein the low molecular vapor deposition film is made of an organic-inorganic hybrid material.   The liquid crystal device according to claim 4, wherein the organic-inorganic hybrid material is silsesquioxane.   4. The liquid crystal device according to claim 3, wherein a material for forming the low molecular vapor deposition film is adamantane.   The liquid crystal device according to claim 3, wherein a material for forming the low molecular vapor deposition film is paracyclopane. In a method for manufacturing a liquid crystal device in which a liquid crystal layer is sandwiched between a pair of substrates,
Forming an alignment film on one side of the substrate;
The method of forming the alignment film includes a step of forming a low molecular vapor deposition film that allows the alignment direction of liquid crystal molecules to be changed from the initial alignment state using a vapor deposition method. In a method for manufacturing a liquid crystal device in which a liquid crystal layer is sandwiched between a pair of substrates,
Performing a predetermined surface treatment on one side of the substrate to form a surface treatment layer;
And a step of forming a low molecular vapor deposition film on the surface treatment layer that can change the alignment direction of the liquid crystal molecules from the initial alignment state by using a vapor deposition method.   The method for manufacturing a liquid crystal device according to claim 8 or 9, wherein a material having no light absorptivity in a visible light region is used as a material for forming the low molecular vapor deposition film.   The method for manufacturing a liquid crystal device according to claim 10, wherein an organic-inorganic hybrid material is used as a material for forming the low molecular vapor deposition film.   The method for manufacturing a liquid crystal device according to claim 11, wherein a silsesquioxane material is used as the organic-inorganic hybrid material.   The method for manufacturing a liquid crystal device according to claim 10, wherein an adamandane-based material is used as a material for forming the low molecular vapor deposition film.   The method for manufacturing a liquid crystal device according to claim 10, wherein paracyclopan is used as a material for forming the low molecular vapor deposition film.

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